Improvement in the mode of heating air for the hot-blast in furnaces



i. JONES.

Hot Blast Oven.

. Patented Dec. 10,1838.

No. was;

blast.

UNITED STATES PATENT OFFICE.

JOSEPH JONES, OF YORK, PENNSYLVANIA.

IMPROVEMENT lN THE MODE 0F HEATING AIR FOR THE HOT-BLAST IN FURNACES.

Specification forming part of Letters Patent No. 1,033, dated December10, 1838.

To all whom it may concern:

Be it known I that I, JOSEPH JONES, of the borough of York, in thecounty of York, in the State of Pennsylvania, have invented certainImprovements in the Construction of 2. Heating Apparatus for Hot-Blastfor Furnaces as are to be Supplied with Heated Air; and I do herebydeclare that the following is a full and exact description thereof.

In the early use of the hot-blast the air was heated in capaciouscylinders or tubes of castiron, the fuel for heating it being containedin ovens or arches,through which the said cylinders or large tubes weremade to pass, the fuel consumed in these ovens not being employed forany other purposethan the heating of the air. Means, however, were soondevised for employing the waste heatfrom the tunnel-head of the furnacefor heating the air to be used in the This has been effected by placingthe oven on the sidevof the tunnel-head and openinga line from it intothe oven. \Vithin this oven are placed a number of tubes, through whichthe air to be heated is forced to pass,

and it has been found that the waste heat so applied has answered theintended purpose; but still it has been evident that a sufficientheating-surface has not been, upon this plan, exposed to obtain all theadvantages from the waste heat which it is well calculated to supply,for it is a'wcll-known fact that although the tubes have beenkeptred-hot the temperature of the blast has been generally but from 500to 600. The object of my first improvement is to obviate this difficultyby such an arrangement of the heating apparatus as shall expose asufficient heating-surface to elevate the temperature ot'the blast toany desired extent. i Y

The general mode oficonstructing the apparatus for heating from thetunnel-head has been to place three cylinders or tubes parallel to eachother and in a horizontal position within the oven, raising them one ortwofeet above the bottom, so that the heat might circulate round them.On the upper side of the middle cylinder therehave been usually tenopenings, and upon the outer ones five, furnished with necks to receivetubes, through which the air to be heated is tocirculate. These tubesare bent in form of the letter U inverted, and their open ends areplaced in the necks above named, five of them connecting each of" thesides with the middle tube or cylinder.

In the accompanying drawings, Figure l. is a perspective view of thefurnace with the oven A upon'it, and Fig. 2 is a view of the arrangementof the tubes constituting the heating apparatus as improved by me, andwhich is contained within the oven At Instead of three, I use fourparallel tubes, B B, the two on each side forming a pair, which areconnected together by the bent tubes 0 O, which rise vertically from BB; When I say bent tubes I refer to form only,not intending to say thatthey are actually bent, the fact being that they are cast in that form.The vertical portions of these tubes will generally be in separatepieces, and will be connected together by the curved upper ends fittingin sockets on them. By this arrangement, with four horizontal cylindersI am enabled to put double 'the number of bent tubes in the spaceoccupied by half the number with the three horizontal pipes. The air tobe heated is blown.

in at the end of one of the outer cylinders at K. It then rises in thefirst tier of ten (or more) verticalpipes and descends through the nexttier into the second cylinder, which communicates by curved end L withthe third cylinder, whence it is conveyed to the fourth in the same wayas from the first to the second. With the fourth cylinder theconducting-pipe D D, leading to the tuyere, is connected. An efi'ectnearly the same as this-produced by the two middle cylinders may beobtained by using in place of. cylinders curve-pipes somewhat like thoseused to connect the up end-of the vertical tubes, or by enlarging themiddle of the horizontalcylinder, and so forming it as to receive adouble row of vertical tubes on each of the above-stated forms, may beused with success; but I consider the firstnamed plan the best and themost permanent.

\Vhat I claim as new and useful in this part of my improvement andinvention is the construction of the pipesin the above-stated forms, soas to obtain the desired effect of increasing the fire-surface by meansof two middle cylinders connected together, with curve-pipes at theirends, and the employment of any of the above-named plans, so as toobtain a double row of vertical tubes in the middle.

Mysecondimprovementconsists in the mode by which I regulate the quantityof heat admitted into the oven by causing the conductingpipe to open orclose a damper operating upon a self-regulating principle, dependingupon the Variations of temperature of the blast which the saidconducting-pipe is exposed to. The

damper E is a flat plate of iron fitted on the top of they oven-chimney,which, by being closed, stops the rush of the flame and heat into theoven. The damper is attached to the end of the long arm of a lever, F,the short end of which is hooked to a rod, Gr, attached to the upper endof the eonductingpipe D, which has a flexiblejoint, by which it isunited to the connecting-tube H. The rod G,,attachedto the short arm ofthe lever, must be made adjustable on that arm, so as completely toregulate the action of this part;

What I claim asmy improvement in this part of the apparatus is theemployment of the hot-air-conducting pipe to open and close a damper inthe chimney, in the manner set forth.

My third improvement is in the manner of constructing a wnter-tuyere soas to cause it to be much less liable to get out of re pair than theWater -tuyeres now employed, and to render itof easy repair when itbecomes necessary. The mode of making such tnyeres heretofore followedhas been to cast them in.

one single piece, forming a chamber near their front ends by means of acore. Such tuyeres, however, are very defective, and are incapable ofbeing repaired. My improvement consists in casting the tuyere in twopieces, in the manner shown in Fig. 3, Where I is the front and J theback end of the tuyere. These parts,

when put together, are secured by suitable bolts and nuts, leaving thehollow chamber and the apparatus for the passage of water as heretofore.

What I claim as constituting my invention in this part of the furnaceis- The casting of the tuyere in two parts, so that the part whichconstitutes its point or t'rontend may be readily renewed Whenever thesame may be necessary.

JOSEPH JONES.

\Vitnesses W. THOMPSON,

LiN'roN THoRN.

